Assuming you extracted a vanilla x64e.rpf from a friend's legitimate Steam backup (which is legally gray but common among modding communities), here is how to install it:
You installed a realistic car pack by replacing files inside x64e.rpf . Now, the mod is outdated, and the game crashes. You didn't back up the original file. You now need the original vanilla x64.rpf to revert your changes. Gta V X64.rpf Files Download
How To Find GTA5.exe File For FiveM - Rockstar, Steam, Epic Games Assuming you extracted a vanilla x64e
If your files are missing or corrupted, do not download them from unofficial sources. Use the built-in repair tools provided by your game launcher: You now need the original vanilla x64
Never trust a direct download link for core game files.
As a GTA V player or modder, you may need X64.rpf files for various reasons: